##Reeves, Chen, Nagano (2003) 2SLS Implementation 
##(last performed on Monday, October 6, 2003 on R version 1.6.2)
##Instruments are TV Ad Cost and Electoral votes (they are excluded from the 2nd stage)

library(sem)
reptv<- tsls(REPTV~REPSTRAT.NEW+DEMTV+COMP+DUMMY92+DUMMY96, 
~EV+COMP+TVADCOST+COMP:EV+COMP:TVADCOST+DUMMY92+DUMMY96)


demtv<- tsls(DEMTV~DEMSTRAT.NEW+REPTV+COMP+DUMMY92+DUMMY96,
 ~EV+COMP+TVADCOST+COMP:EV+COMP:TVADCOST+DUMMY92+DUMMY96)


demapp<- tsls(DEMPREZ~DEMSTRAT.NEW+REPPREZ+COMP+DUMMY92+DUMMY96,
 ~EV+COMP+TVADCOST+COMP:EV+COMP:TVADCOST+DUMMY92+DUMMY96)

repapp<- tsls(REPPREZ~REPSTRAT.NEW+DEMPREZ+COMP+DUMMY92+DUMMY96,
 ~EV+COMP+TVADCOST+COMP:EV+COMP:TVADCOST+DUMMY92+DUMMY96)
